Build Log-Foam Trainer-Electric

Started by Bilal, December 24, 2012, 02:19:11 AM

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Bilal

hello everyone,
my exams got over yesterday, so now am up on another scratch build, specifications of which are described below

Type- high winger with aelirons
Specifications- wingspan 37', chord 7', fuse length 24', AUW ~300gm
Construction material- high density thermocol(will come to this later)
Powerplant- electric, 800kv bldc+ 1045 SF prop
Plan- from RCG, here is the link http://www.rcgroups.com/forums/showthread.php?t=1391606

Now coming to the construction material....the foam/thermocol am using is a pretty cool material I accidently laid my hand on, its a micro grain high density foam with grain size~ 1mm and comes in a thickness of 6mm and 10mm, it is available here at the stationary stores by the name of high density thermocol.

It is easily availaible, and as one of my architect friends (Abhay1290) told me is used to build architectural models. One sheet of this foam 3.5'X2.5' cost me Rs40, so its pretty cheap too.

I've finished the wings and ritenow am working on the tail feathers.....will post the pics as i proceed

one more thing fellas, I need suggestions on a couple of things,
1. which glue should I use for gluing foam.....am using fevicol ritenow but its too slow
2. what should I use as the spar?
3. the plan suggests slightly under-chambered wing...so please suggest some method to induce chamber in an otherwise flat wing
4. how to make the undercarriage strong enough to withstand the force of landings....as everything is foam here?
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

here comes the wing and the tail feathers
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

fuselage sides cut......it is slowly taking shape
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

rastsaurabh

#3
Cool Bilal...... where is it you are going to put the motor ? make a Plus at the nose for extra strength ( as in 3D  planes)

Spar can be only carbon --- as no other material is possible in small planes ( try balsa / bamboo skews)

Also for fuses put a bandage patti in between and stick , post that cover with brown paper cover for extra strength.
You can also sandwich a bamboo skewer in fuse.

For under cambered cut the shape in fuse as per the reqd so that the wing takes the shape of the cut. in the edges make ribs (as you make with balsa ) and stick underside of wing with pressure this will give shape to the wing in case it is warped atleast give 2 such ribs. hope you understood what i am trying to say.

Fevicol is the best.... else try foam safe glue/ 5min epoxy from HK but its going to be expensive.

This plane of yours is very close to one i was planning to make..... Can you share the plans...

Ailerons ?? are there any ?

Your cutting skills are exceptionally good  :thumbsup:

Bilal

first of all sir, thanx for liking my work

sir, this isn't a 3d plane as it might seem from the last pic(i just placed the component together to get a feel of what it gonna look like)......it is actually a full fuse foamy with box type fuselage....those are just the fuse sides you see in the pic. The fuse stilll needs the top and bottom, and a bit sanding ;D

i can't share the plan on the forum as their might be copyright issues, but gimme your email and i'll mail you the entire package along with the build pics.

am using fevicol at the moment.....but i heard somewhere that pidilite makes a foam safe glue that works best in case of thermocol......its just that i can't remember the name :banghead:

As far as the spar is considered, i don't have access to CF......so i was thinking of using either the glass fiber rods i have lying around or bamboo skewers used by the florists....am still confused :headscratch:

the original plan suggested a slightly under-cambered Kfm airfoil.....but i want it to be an under-chambered clark-y (i just don't like the look of KFm airfoil) as shown in the second pic.....so which would be better ???

for forming  the chamber I thought bending the wing over a form while heating it with a heat gun, but your idea seems better.....because with heat gun, one slip of hand and vola! you got a hole in your wing :giggle:

will keep the folks here updated,

happy holidays
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

abhay

nice going bilal,

i just returned from my trip..
i am eager to see the progress...

would be visiting you tomorrow...
keep it up
I can take off and fly well. Its landing which sucks :banghead::banghead:

Bilal

here is the update,

center block completed and the tail surfaces are covered in newspaper....i did this to provide strength

folks, I still need suggestions on using either the Kfm airfoil or regular clark-y with slight under-chamber :headscratch:......and also on forming the chamber in the wing......seniors kindly pitch in :help: 
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

the bigger square hole in the center block is for the servos and the adjacent slot is for the control rods
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

rastsaurabh

good going Bilal..... how good it was if we could buy from some shop the items in your last pic...as a kit.

Bilal

hahaha.........if shipping wasn't an issue.....I would have made a kit for you, sir. But i can still offer you one when you visit Lucknow next time
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

I returned to hostel a couple of days ago and resumed building.......here is what i have build so far

I have chosen kfm1 airfoil for this plane just because of the ease of building

Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

the wing's leading edge is sanded to an aerodynamic shape upon gluing the step
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

the LE has come out pretty smooth and uniform, much better than what I expected.........the wings are to be joined with a spar in between to provide the correct dihedrel which is 7 degrees for each wing half
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

the motor would be screwed to a piece of 3mm plywood which I would then glue to the fuse.....hopes it stays on with all the pull from the propellor 8-)
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

and this is how it come up.........pretty much identical to the cad drawing
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

I think the pics are pretty much self explanatory, but if still anything bugs you, feel free to ask questions

and suggestions are welcome for the paint scheme
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

abhay

bilal, i cant resist to see this beauty soon.
I am glad the way you figured out to make the dihedral..

Any guesses for the weight you have gained so far??
I can take off and fly well. Its landing which sucks :banghead::banghead:

arun.sreelakam

good work bilal... looks cool..  {:)} {:)} {:)}
And i do know the weight will be lightest, coz of thermocol foam...
Turnigy i10|Flysky 9xb|Hoverfly quadcopter|Arduflyer apm 2.5 with gps|Pixhawk|Homemade micro night vapour|Homemade ornithopter(in progress)| Reptile Quad with Gopro Brushless gimbal | Naza v2| APM 2.6 with GPS | Micro quad self made | FrSky| v911 Helis | 1200mm Hexacopter with 5d gimbal | 1300mm x8 With Red Gimbal | 1000mm Octo|

sanjayrai55

Very good build. I wish there was some way you could make the joint between your motor ply firewall and the fuse more failsafe

manojswizera

Bilal how the wood for dihedreal is cut in that shape or uses something else ???
Russ-40 Trainer, Mr.moss, Pushler, Skysurfer, Mugi , F-22, Red swan, Xtra-300, redfury, flying mantaray.

Bilal

Swizera sir, the wood has been cut by hand using coping saw
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

veloci

Cool build, Bilal  {:)}
Looking forward to the flight video.....
Airplanes may kill you, but they ain't likely to hurt you.
~~~Satchel Paige

Bilal

Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

thanx Veloci sir, video would take some time......probably another weekend
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

veloci

Hey i'm still in my final year of engineering........technically not old enough to be called 'sir'....   ;D
:giggle:
Airplanes may kill you, but they ain't likely to hurt you.
~~~Satchel Paige